It would seem to be the Windows dialog box malfunctioning, but no other program has this problem
It might be something to do with the fact that SlickEdit presents a "customized" file open dialog. Do the applications where the file open dialog works use a customized or non-customized dialog. You can see the non customized dialog by doing file open in Notepad.
Does it make any difference if you initiate the file open using Ctrl-O, the toolbar or the File menu?
SlickEdit used to have a Windows 3.1 style file open dialog option but this seems to be gone from Slick 2009.
Googling for "file open dialog" hangs - finds a couple of suggestions - doesn't sound like your problem though.
1. Windows is hunting for icons
2. Your path has a non-existent network path in it.
To see the path setting you can open the build toolbar and type path. SlickEdit adds the slick installation "win" folder to the path.
For the icon thing, the suggested solution is this
Goto this key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Explorer\Shell
Icons
Just delete Shell Icons or rename it and the problems will go away. It
will force the shell to just goto shell32.dll for icons.
Another thing I saw mentioned was that stardock "windowblinds" can cause problems. Have you installed any skinning/theme stuff recently?
Graeme